Center stable polar relay



May 26, 1959 A. J. KoDA ETAL 2,888,533

CENTER STABLE POLAR RELAY Filed Jan. 2s, 1958 INV ENT ORS Aer/Jue J. A/oDA ,4A/D BY dof/M N SCA/WELL ATrvkA/Evs.

United States Patent @ffice 2,888,533 Patented May 26, 1959 Clare & Company, Chicago, Ill., a corporation of Delaware Application January 23, 1958, Serial No. 710,643 6 Claims. (Cl. 200-93) This invention relates to a relay construction and, more particularly, to a new and improved center stable polar relay. The relay of the present invention is an improvement in the relay disclosed in the copending application of Wilhelm Juptner, Serial No. 677,275, filed August 9, 1957, which copending application is assigned to the same assignee as the present application.

The above identified application discloses a side stable polar relay in which an armature pivotally mounted within a coil is selectively displaced in opposite directions in response to the energization of the coil by signals of opposite polarity. In this relay, the field structure comprises two separate heel pieces forming two spaced pairs lof polefaces which form two gaps spaced longitudinally of the armature and in which the ends of the armature are disposed. The two heel pieces are magnetically biased to opposite polarities by a permanent magnet so that, when the armature is displaced into proximity to a single poleface on each of the heel pieces to bridge the gap therebetween, the magnetic biasing means retains the armature in this displaced bridging relationship until such time as an operating signal of an opposite polarity is applied to the winding. The heel piece, the coil, and the armature are held in an assembled relation by a supporting structure which at least partially encloses these components.

One object of the present invention is to provide a center stable polar relay in which the contact actuating armature is automatically restored to a normal or neutral position at the end of each relay operation.

Another object is to provide new and improved means for restoring a pivoted armature in a polar relay to a normal position following each relay operation.

A further object is to provide new and improved means for converting a side stable polar relay into a center stable relay with a minimum cost and effort.

Another object is to provide a supporting structure for a polar relay including a member having an upturned portion on which is mounted a U-shaped spring for centering a pivotally mounted armature.

In accordance with these and many other objects, an embodiment of the invention comprises an operating winding or coil having a centrally disposed opening in which is pivotally mounted an armature. A pair of separate and somewhat U-shaped heel pieces are disposed adjacent the operating winding with four side surfaces disposed adjacent the armature to provide two pairs of opposed polefaces defining a pair of gaps in which the opposite end portions of the armature are disposed. A permanent magnet interconnects the bight portions of the heel pieces to bias the two polefaces on one heel piece to one polarity and to bias the two polefaces on the other heel piece to an opposite polarity. Thus, when the operating coil is energized by an input signal, the armature is pivoted into a bridging relation in which one end of the armature is disposed in proximity to a poleface on one of the heel pieces and the other end of the armature is located in proximity to a poleface formed 0n the other heel piece. A pair of residual plates which cover the four polefaces are engaged by the opposite ends of the armature to prevent the armature from being held in the displaced position because of the flux field due to the permanent biasing magnet. The heel pieces, the operating winding, and the armature are held in an assembled relationship by a supporting structure comprising a plurality of rigidly connected plates which at least partially enclose these components.

The relay construction further includes a plurality of contact spring assemblies or pile-ups which are secured to the sides of the relay construction and which are connected to the upper end of the armature by a dielectric actuator element. Thus, when the armature is deflected to either of its displaced positions in accordance with the polarity of the signal applied to the operating winding, the contact spring assemblies are selectively operated. To provide means for restoring the armature to a normal or neutral position when the operating signal is removed from the winding, an upper plate of the supporting structure is provided with an aperture through which the upper end of the armature extends to be engaged by the actuator element. r[his upper end of the armature is further provided with a pin which is received between the ends of a U-shaped at spring which extends generally transverse to the armature in a direction generally parallel to its pivotal axis. This upper plate of the supporting structure is further provided with two integrally formed upstanding portions, one of which is notched to receive the bight portion of the U-shaped spring and the other of which is received between the arms of the spring at a point disposed between the bight and the ends of the arms thereof. This U-shaped spring is so formed that when the armature is pivoted in either direction, the pin bears against one or the other of the two spring arms and deects it in moving to the displaced position in which the residual plates are engaged by the opposite ends thereof. The force of the spring resisting this deilecting movement of the armature is less than the displacing force provided by the energization of the coil. However, the force of the spring tending to return the armature to its normal or neutral position is greater than the force provided 4by the biasing magnet so that, as soon as energization is removed from the operating winding, the deected spring arm overcomes the force of the biasing magnet and restores the armature to its centrally disposed normal or neutral position in which the opposite sides of the pin are engaged by the two spring arms.

Many other objects and advantages of the present invention will become apparent from a consideration of the following description thereof when taken in conjunction with the following drawings in which:

Fig. l is a front elevational view in partial section of a relay embodying the present invention;

Fig. 2 is a cross-sectional view taken along line 2 2 in Fig. 1 assuming that the entire relay construction is shown therein;

Fig. 3 is a top elevational view of the relay shown in Fig. l with the upper portion of the protective housing therefor removed; and

Fig. 4 is an exploded perspective view of means ineluded in the relay construction for restoring the armature thereof to a normal or neutral position.

Referring now more specifically to the drawings, therein is shown a center stable polar relay indicated generally as 10 which embodies the present invention. This relay is of the general type disclosed in the above identified copending Iuptner application in including a coil assembly 12 disposed adjacent a magnetically biased eld structure 14. When the coil assembly 12 is energized, an armature 16, which is pivotally mounted within the coil assembly 12 for movement about a centrally disposed axis, is pivoted in either a clockwise or counterclockwise direction (Fig. l) to one of two displaced or eXtreme positions `in accordance with the polarity of the signal applied to the assembly 12. In moving to this position, a pair of contact spring assemblies or spring pile-ups 1S and 2l) are selectively operated in accordance with the direction of movement of the armature 16. In the relay described in the above identified Juptner application, the armature 16 is magnetically retained in the extreme or displaced position by the holding force provided by the magnetically biased field structure 14.

However, in accordance with the present invention and in order to provide a center stable rather than a side stable polar relay, the relay 16 is provided with a centering assembly indicated generally as 22 (Fig. 4) which is effective to automatically restore the armature 16 to its normal or neutral position (Fig. l) as soon as operating signals of either polarity are removed from the operating winding assembly 12. The assembly 22, which renders the relay it? center stable, is easily provided merely by modifying a portion of a supporting structure indicated generally as 24 which holds the coil assembly 12, the eld structure 14 and tne armature 16 in a predetermined assembled relationship. "illus, side stable relays of the type disclosed in the above identied Iuptner application and center stable relays of the type embodying the present invention can be provided at a reduced cost and without the necessity or" maintaining a complete inventory of parts for each of these two types of relays. The supporting structure 24 includes a depending portion 24a which is secured to a base plate 26 to provide a means ior mounting the relay 10. If desired, the relay can be enclosed in a suitable housing or dust cover 28 which is secured to the base plate 26.

Referring now more specically to the operating coil assembly 12, this includes a bobbin 3l) on which a coil 32 is wound and which provides a centrally disposed opening 34 in which is disposed a generally U-shaped armature mounting element 36. A pivot pin 33, the ends of which are received in the legs of the U-shaped element 36, rotatably supports the armature 16 within the opening 34 for pivotal movement about an axis generally disposed midway along the length. of the armature 16.

The eld structure 14 includes la pair of similar U- shaped heel pieces 46 and 42 between the bight portions of which is disposed a permanent magnet 44 (Fig. 2) which magnetically biases the heel piece 40` to assume a rst polarity and the other heel piece 42 to assume an opposite polarity. The ends of the legs of the heel pieces 40 and 42 each provide a pair of pole pieces 40a and b and 42a and b which are disposed adjacent and on 0pposite sides of the upper and lower ends of the armature 16 to provide two gaps spaced longitudinally along the armature 16. A pair of residual plates 46 and 48, which are disposed within the opening 34 and extend generally parallel to the armature 16, cover the pole pieces 40a and b and 42m and b to reduce the forces tending to hold the armature 16 in either of its displaced or extreme positions.

When an operating signal of a given polarity is applied to the winding 32, the opposite ends of the armature 16 assume opposite polarities in accordance with the polarity of the signal applied to the winding 32. Thus, the armature 16, is dellected in either a clockwise or counterclockwise direction (Fig. l) to concurrently engage the residual plates 43 and 46 either in proximity to the pair of spaced pole pieces 40a and 42b or the pole pieces 42a and 46h in accordance with the polarities to which the heel pieces itl and 42 are biased by the magnet 44. In these displaced or extreme positions, the biasing magnet 44 is bridged by the armature 16 and, accordingly, provides a force tending to hold the armature 16 in its displaced position ollowing the termination of the energize.- tion of the winding 32. However, this holding force is reduced by the residual plates 46 and 48 and, as set forth in detail below, is overcome by the restoring forces provided by the deliected springs in the pile-ups 18 and 20 and by the assembly 22.

In shifting to a displaced position, the contact spring assemblies 18 and 2lb are actuated by the armature 16 by means of a dielectric actuator plate 50 which is coupled to an upper end of the armature 16 and which is also connected to movable contact springs 18a in the assembly 18 and movable contact springs 26a in the assembly 20; Thus, the contact spring assemblies 18 and 20 are selectively operated in accordance with the direction of displacement of the armature 16. In being dellected, the movable springs 18a and Ztla also provide a component of force tending to restore the armature 16 to its normal position.

Referring now more specifically to the armature restoring assembly 22 embodied in the present invention, this assembly includes a concaved plate 52 which forms a portion of the supporting structure 24 for maintaining the winding assembly 12, the iield structure 14, and the armature 16 in an assembled relationship. The plate 52 (Fig. 4) includes a centrally disposed opening 54 throughwhich the upper end of the armature 16 extends. 'The plate 52 further includes a irst integrally formed upstanding portion 56 which is bifurcated to provide a pair of slots 56a and 56h and a second integrally formed upstanding portion 58 which is aligned with the upstanding portion 56 and the upper end of the armature 16 when the armature is in its normal or neutral position. To provide means for restoring the armature 16 to its neutral position when the energizing signal is removed from the winding 32, a U-shaped hat spring, indicated generally as 60',v is provided having a pair of free resilient arms 60a and 613i) which are connected by a bight portion 60C. The bight portion 66C is mounted on the rst upstanding portion 56 with the arms 69a and 60h disposed in the slots 56a and 56h, respectively. With the spring 60 thus mounted on the upstanding portion 56, the ends of the arms 69a and 66E: engage the opposite sides of a pin 62 which is mounted in a recess in the upper end ofthe armature 16. Further, the intermediate portions of the arms 66a and lib engage the sides of the second vupstanding portion 5S.

Thus when the relay 19 is operated to deflect the armature 16 in either direction to one of its displaced positions, the `force provided by the energization of the winding 32 exceeds the restoring forces provided by force v. displacement characteristics of the deflected movable springs 18a and 2da in the contact spring assemblies 1S and 20 and also the restoring force provided by the force v. displacement characteristic of the deliected one of the spring arms 60a and 61H7. However, when the energization of the coil 32 is terminated, the restoring forces provided by the dellected one of the arms 60a and 6tlb and by the deflected springs 18a and 20a eX- ceeds the holding force provided by the biasing magnet 44, and the armature 16 is restored to the neutral or normal position illustrated in Fig. 1.

The U-shaped spring 60 also provides means for preventing overtravel of the armature 16 when it is restored to its neutral position. More specifically, the ends of the resilient arms 69a and 60h are prestressed so that, in the normal position of the armature, the ends of these arms engage the sides of the locating means 58 and the opposite sides of the pin 62. Thus, equal force couples are applied to the armature 16 tending to hold it in itS normal position. When the armature 16 is restored to the neutral position illustrated in Fig. l under the Control of the deflected one of the arms 60a and 60b vupon'release of the relay 1G, the pin 62 engages the stationary one of the arms 60a and 69h and causes the abrupt application of a substantial force to the armature 16 tending to oppose its inertia induced overtravel. Thus, any overtravel of the armature 16 on restoration of the relay which may result in improper contact operation is positively prevented. Further, the prestressing of the spring arms 60a and 60b prevents any movement of the armature 16 from its normal position due to Vibration because any clockwise or counterclockwise displacement thereof results in the abrupt application of a large restoring force.

Although the present invention Ihas been described in conjunction with a single illustrative embodiment thereof, it will be understood that numerous other modifications and changes may be made therein by those skilled in the art which will fall within the spirit and scope of the principles of the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A center stable polar relay comprising a magnetically biased field structure including two pairs of opposed pole pieces, each of said pairs of pole pieces dending a gap; a winding having a centrally disposed opening; an armature pivotally mounted within said opening, each end of said armature being disposed within one of said gaps; supporting structure for holding said iield structure and said winding in an assembled relationship and including a wall element dening both an opening and an upstanding portion, one end of said armature projecting through said opening; Contact means connected to and operated by said armature; and spring means secured to said upstanding portion and including a pair of spaced and generally parallel spring arms engaging opposite sides of said one end of said armature to hold said armature in a position spaced from all of said pole pieces.

2. The relay set yforth in claim l in which a locating element carried on said wall element is disposed between said pair of spring arms.

3. A center stable polar relay of the type including an armature adapted to be pivoted from a normal position in opposite directions toward diiierent opposed pairs of spaced pole pieces in accordance with the polarity of an operating signal applied to a winding; the combination comprising a relay supporting structure for holding the Winding, the pole pieces, and the armature in an assembled relationship; a rst upstanding element formed integral with said supporting structurer; a U-s'haped spring having both a bight portion connected to said upstanding portion and a pair of free end portions which are stressed to bear against opposite sides of said armature, said spring normally holding said armature in said normal position and resiliently opposing displacement of said armature from said normal position; and a second upstanding element formed integral with said supporting structure and disposed between the `free ends of said U-shaped spring at a point adjacent said armature.

4. In a relay construction including a coil, an armature pivotally mounted Within the coil, and a `iield structure disposed adjacent the coil and the ends of the armature; the combination comprising a plural part supporting structure for securing the coil, the armature, and the field structure in an assembled relation, said supporting structure including a plate; a notched portion integr-a1 with and projecting upwardly from said plate substantially parallel to said armature; and a U-shaped spring having a bight portion and a pair of arms, the bight portion of said spring being positioned in said notched portion with the arms extending transverse to and engaging opposite sides of an end of said armature.

5. A center stable polar relay comprising a magnetically biased field structure providing two pairs of spaced polefaces, each of said pair of polefaces defining a gap; an operating winding disposed adjacent said eld structure and including a centrally disposed opening; an armature pivotally mounted within said opening with its end portions disposed within said gaps but spaced from said pairs of polefaces; the energization of said winding producing a force of a iirst value for pivoting said armature in one of two opposite 'directions to a displaced position adjacent said polefaces in accordance with the polarity of the signal applied to said winding, said magnetically biased iield structure providing a second force tending to hold said armature in said displaced position when the operating signal is removed from said winding; a contact spring assembly actuated by said armature and including resilient movable contact means which are deliected when said armature moves to said `displaced position; a supporting structure for holding said winding and said field structure in an assembled relationship and including a member extending substantially transverse to said arma` ture; an upstanding portion on said member; and a spring element carried on said upstanding portion and having two resilient arms extending substatially transverse to said armature and engaging opposite sides of one end of said armature when said armature is in said normal position, each of said resilient arms having force v. displacement characteristic such that the arms and the deflected movable contact means provide a force resisting movement of said armature to said `displaced position which is less than said first force `during movement of said armature from said normal position to a displaced position and 4also provide a force for restoring said armature to said normal position from said displaced position which is greater than said second force.

6. The relay set forth in claim 5 including locating means carried on said member and extending upwardly therefrom parallel to said armature in its normal position and disposed between said resilient arms.

References Cited in the tile of this patent UNITED STATES PATENTS 946,489 Clement Jan. 11, 1910 1,333,247 Cummings Mar. 9, 1920 2,436,354 Burke et al. Feb. 17, 1948 2,731,527 Marsh Jan. 17, 1956 2,767,279 Hall Oct. 16, 1956 2,811,602 Rommell et al. Oct. 29, 1957 

